Electrical measuring instrument.



C. T. ALLCUTT.

ELECTRICAL MEASURING INSTRUMENT.

APPLICATION -F|LED 05c. 20. 1916.

1 ,289,068. Patented Dec. 31, 1918.

WITNESSES I INVENTOR a il /vesfer 7. AI/cuff wwk , AT ToRNEY UNITEDSTATES P T T OFIfiC-Q...

cnnsrnn rpamcn'rr, or WILKINSBURG, rnnns nvania, essrsnon ro fnns'rrnsg.

HOUSE ELECTRIC & MANUFACTURING VANIA.

COMPANY. A CORPORATION OilElll'NSXL- ELECTRICAL MEASURING INSTRUMENT. I

Specification of Letters Patent. Patented 311i, 15 18.

Application filed December 20, 1916. Serial No. 138,035.

To all 'l /J/LOl/L it may concern Y Bent known that I, CHESTER T.'ALLCUTT, a citizen f the United States, and a resident of Wilki shurg,in the county of Allegheny and State of Pennsylvania, have invented anew and useful Improvement in Electrical Measuring Instruments, of whichthe following is a specification.

-My invention relates to electrical measuring instruments andparticularly to high-. voltage measuring instruments of the-visibledischarge or corona type.

The object of myinvention is to provide a measuring instrument of theabove indicated character that shall have means formdicating thepos1t1on of the corona discharge on a tapered conductor and,consequently,

the value of the voltage impressed thereon.

Hcretofore, the ionization of the air by the presence of corona has beenutilized for determining relatively high voltages. However, since thecorona emanations are visible only in a dark room, it is desirable to'pro' vide a device of this character that may be used in any place. r

In the carrying out of my invention, I

provide means, such as an electroscope, for

indicating when corona appears and a shield for the tapered conductorfor so changing its relative diameter that the positionof the shield,when corona appears, shall be an indication of the voltage.

In the accompanying drawings, Figure l is a sectional view of ameasuring device embodying my invention, and Fig. 2 is a view takenalong the line H 'll of Fig. l.

A high-voltage electrical circuit 1, the voltage of which is to bedetermined, is operatively connected to a tapered conductor 2 H rlog;

where E is the surface intensity or electri-- cal intensity at thesurface of the tapered conductor 2, V is the voltage applied between theconductor 2 and the cylinder 3 and 4' and R are the radii of thetaperedconductor 2 and the inner-wallotthe outer cylindrical member 3,respectivelyfiwlt will be seen-that corona will appear-at dillerentpoints along the tapered conductor-21amcording to its surface intensityand then dius of the same. That is, if the' a'ppliecl voltage is justsuflicientto cause corona em anations from the tapered conductorQ at thepoint 4-, and the pointfl'may be accurately determined, i" is understoodthat an accurate means maybe Obttlll'lGCl' for determming the value ofthe applied voltage.

means, such as an electroscope provided 1 for determining when corona'appears'andi means 6 is provided for determining the" point along thetapered conductor :Zatvvhich" it occurs, an accurate indication" of theVolta ago iinprcssed across the circuit l na -ts" 7 along'its lengththat conimunicates'witi an incl'osed compartment 8 inWvhichisdis' 1posed a'conductor 9 that is insulated from the cylinder 3-by insulatingmembers 10 and Gold leaves '12 are'secured' to the cora ductor 9 at itslower end to thus constitute the electroscope '5.

suitable source of electroin'otive force (not ionization, the' leaves 12will collapse to'in dicate the presence'of corona aroun'r eco'n dnetort'rically connected thereto at one end and.

movable longitudinally thereal-ong? for the 'purpose of so varying the.relative"radius" and, consequently, the surface intensity of the taperedmember 2 that the position at which corona occurs on the member 2 may beaccurately determined. A scale 1-3: is marked on the member 13 and isadapted to coop- 10o crate with a pointer 15 to indicate the position ofthe member 13. The scale 14: may be calibrated in volts if it is sodesired.

In the operation of the device, the movable member 13 is moved along theconductor 2 member 13 will serve to indicate the position 11o 9o A.conducting cylinder lii' is'disposed about the tapered conductor 2 andissuitably elec-'"-' on the conductor 2 at which the corona occurs.Thus, if the radius of the conductor 2, at this point, is known and,consequently, its surface intensity for this point will be know, then,from the expression rious modi cations without. departing from thespirit and scope of the invention as set forth in the appended claims.

I claimasmy invention 1 A'hi'gh 'v'oltage measuring instrumentcomprisingtwo concentric conductors, one of which is cylindrical and the othertapered, means for indicating the presence of corona surrounding thetapered conductor and a ngovable means engaging the tapered conductdrfor indicating, by its position, the position along the taperedconductor at which corona appears. p

2. In r measurin device, the combination with a tapered con uctor, acylindrical conductor concentrically disposed with respect to thetapered conductor, and means for indicating the presence of coronaaround the tapered conductor,- of a movable conducting means engagingthe tapered conductor for indicating the position along the taperedconductor at which corona appears.

3. In a measurin device, the combination with a tapered con uctor, acylindrical conductor concentrically disposed with respect to thetapered conductor, and 'means for indicating the presence of coronaaround the tapered conductor, of a conductor concentric, and inengagement, with the tapered conductor for precluding the emanation ofcorona under predetermined conditions and for indicating the position onthe tapered conductor at which corona appears.

' 4. A high-voltage measuring device comprising a tapered conductor, amain conucting' cylinder concentric with respect to the taperedconductor and a cylindrical conductor surrounding the tapered conductorfor indicating, by its position with respect to the tapered conductor,the difference in potential between the main cylinder and the taperedconductor.

5. In a measuring device, the combination with a tapered conductor, acylindrical conductor concentrically disposed with respect to thetapered conductor, and means for in-' dicating the presence of coronaaround the tapered conductor, of a conducting barrier for the taperedconductor having a scale thereon for indicating the position of coronadischarge.

(3. In a measuring device, the combination with a tapered conductor, acylindrical con ductor concentrically fdlSPOSBCl'Wlth respect to thetapered conductor, and means for indicating the presence of coronaaround the tapered conductor, of a movable conducting barrier adapted toengage the tapered conductor and having a scale thereon for indicatingthe position of coronadischarge.

7. In a voltage-measuring device for a high-voltage electric circuit,the combination with a tapered conductor connected to one conductor ofthe circuit, a conducting cylinder connected to the other conductor ofthe circuit and disposed concentrically with respect to the taperedconductor, and means for determining when corona is present around thetapered conductor, of means electrically connected to and relativelymovable with respect to the tapered conductor for indicating theposition of the corona discharge.

8. In a high-voltage measuring device, the combination with a taperedconductor, a con ducting cylinder concentrically surrounding the same,and means for indicating when ionization is set up by the formation OVIFcorona around the tapered conductor, of a conducting member surroundingthe tapered conductor for determining the position of the coronadischarge.

In testimony whereof, I have hereunto subscribed my name thisl5th day ofDec,

. CHESTER T. ALLCUTT.

